<p>This paper seeks to identify the leading social, economic, political, and cultural barriers to the adoption of climate-smart agriculture in Kenya. The study is based on primary qualitative data collected from 146 farmers in Southern Kenya, 22 key informants, and a targeted literature review. We employ a five-stage process-tracing technique with Bayesian updating to trace causal pathways between low CSA uptake and possible alternative explanations. We find poverty and access to financial resources are the leading explanations for low CSA uptake. This barrier was raised in all three evidence sources with high frequency. We observe a disconnect between farmers’ experiences and the support provided by public and private actors that tends to focus on education and training. We conclude that farmers in the sampled regions are motivated to take up CSA practices, but most will be unable to adopt CSA without direct financial or in-kind support. We draw recommendations from our analysis to support more effective and efficient support for smallholder farmers in Kenya and in other low-income contexts. Although our results are limited to the contexts we study, the methodological approach we use that gives primacy to farmers’ explanations for CSA uptake is shown to be a useful tool that can be replicated to inform tailored support to CSA in other contexts.</p>